<!DOCTYPE html>
<html lang="en">

  <head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
  </head>

  <body>

  </body>
  <script>
    /* 
    
    */
    const banji = {
      name: "终极一班",
      students: [
        'grace',
        'jason',
        'tom',
        'knight'
      ],
      [Symbol.iterator]() {
        //1.声明一个索引变量
        let index = 0;
        //2.将this传导正确
        let _this = this;
        return {
          next: function () {
            if (index < _this.students.length) {
              const result = {
                value: _this.students[index],
                done: false
              }
              //3.下标自增
              index++
              //4.返回结果
              return result
            } else {
              return {
                value: undefined,
                done: true
              }
            }
          }
        }
      }
    }

    //遍历这个对象
    for (value of banji) {
      console.log(value);
    }
  </script>

</html>